1. Field of the Invention
The invention relates to a paper sheet discharge apparatus, in particular, to a paper sheet discharge apparatus for receiving, sorting, and accommodating paper sheets, such as print paper sheets discharged from a printing apparatus, such as a printer.
2. Description of the Related Art
Conventional recording medium discharge apparatuses have been used to receive, sort, and accommodate recording media, such as paper sheets discharged from an image-forming apparatus or a printing apparatus, such as copying machines, printers and facsimiles.
Such a recording medium discharge apparatus is disclosed, for example, in Japanese Patent Application Laid-Open No. 1-197277, which includes a plurality of bins for storing paper sheets, and a pair of transport rollers for receiving paper sheets discharged from an image-forming apparatus and discharging them to a predetermined discharge position, wherein the plurality of bins are vertically moved upwardly and downwardly to the fixed discharge positions of the pair of transport rollers so that the paper sheets are sorted into paper sheets stored in the respective bins.
U.S. Pat. No. 5,551,686 (corresponding to Japanese Patent Application Laid-Open No. 8-259093) describes a system that includes a plurality of fixed bins, moving belts for transporting paper sheets discharged from an image-forming apparatus, in an alignment direction of the plurality of bins, and gates provided corresponding to the respective bins, for changing the direction of transport of the paper sheets by the moving belts so that the paper sheets are guided to the corresponding bins.
However, it has also been recently required that the image formation process be performed at high speed, in accordance with which it is also required to perform, at a high speed, the process of sorting and accommodating the paper sheets discharged from the image-forming apparatus. In the case of the apparatus in which the plurality of bins are vertically moved upwardly and downwardly to the fixed discharge position of the pair of transport rollers, it takes a long time to vertically move the bins, and it is difficult to accelerate the sorting and accommodating process. In the case of the system in which the paper sheets, which are discharged from the image-forming apparatus, are transported by using the moving belts, and the transport direction is changed by using the gate to discharge the paper sheets to the respective bins, the rearward end of the paper sheet may not be able to be discharged reliably to the bin if the resistance between the paper sheet and the bin is large when the paper sheets are fed from the moving belts to the respective bins. Therefore, such a system can become jammed with the paper sheets, for example. Further, in the case of any one of the conventional recording medium discharge apparatuses and systems, the increase in load exerted on a driving source, and the noise generated during operation, cause problems when attempting to attain high speed performance.
Japanese Patent Application Laid-Open No. 9-175714 discloses a paper sheet discharge apparatus that includes multiple stages of delivery units provided in an integral manner to make it possible to distribute paper sheets discharged from a paper sheet-processing unit. The delivery unit includes a tray for accommodating paper sheets, a receiving port for receiving the paper sheets transported from the paper sheet discharge apparatus, a transport means for transporting the paper sheets transported from the receiving port, a discharge port for allowing the paper sheets transported by the transport means to be discharged to the receiving port of the delivery unit, and a guide means for guiding the paper sheets imported from the receiving port to the tray or the discharge port (claim 9 in Japanese Patent Application Laid-Open No. 9-175714). The paper sheet discharge apparatus further includes a driving unit through which the delivery unit is installed to a printer. The driving unit guides the paper sheets exclusively into either the delivery unit or a discharging stacker of the printer.